Physicochemical and histochemical characteristics of bovine longissimus lumborum muscle defected as muscular steatosis (massive adipocyte infiltration).

To understand muscular steatosis observed in beef carcasses, physicochemical and histochemical characteristics were compared between abnormal (massive fatty replaced) and normal regions of beef striploin. Fat content in the abnormal region (48.02%) was approximately twice than that in the normal region (22.01%). However, fatty acids did not show significant (P > 0.05) differences in their compositions between the two regions. Tenderness was significantly (P < 0.05) higher in the abnormal region. However, other meat quality traits were not significantly (P > 0.05) different between the two regions. Massive accumulation of adipocytes was accompanied by muscle fiber atrophy regardless of muscle fiber types. Without a change in total muscle fiber density, oxidative fiber composition was significantly increased, whereas glycolytic fiber composition was decreased (P < 0.05). These findings suggest that adipogenic transdifferentiation and muscle fiber type switching can occur within the muscle due to muscular steatosis.

The Role of Human Umbilical Vein Endothelial Cells in Osteogenic Differentiation of Dental Follicle-Derived Stem Cells in In Vitro Co-cultures.

Angiogenesis and vascularization are essential for the growth and survival of most tissues. Engineered bone tissue requires an active blood vessel network for survival and integration with mature host tissue. Angiogenesis also has an effect on cell growth and differentiation in vitro. However, the effect of angiogenic factors on osteoprogenitor cell differentiation remains unclear. We studied the effects of human umbilical vein endothelial cells (HUVECs) on osteogenic differentiation of dental follicle-derived stem cells (DFSCs) in vitro by co-culturing DFSCs and HUVECs. Cell viability, based on metabolic activity and DNA content, was highest for co-cultures with a DFSC/HUVEC ratio of 50:50 in a 1:1 mixture of mesenchymal stem cell growth medium and endothelial cell growth medium. Osteoblastic and angiogenic phenotypes were enhanced in co-cultures with a DFSC/HUVEC ratio of 50:50 compared with DFSC monocultures. Increased expression of angiogenic phenotypes and vascular endothelial growth factor (VEGF) levels were observed over time in both 50:50 DFSC/HUVEC co-cultures and DFSC monocultures during culture period. Our results showed that increased angiogenic activity in DFSC/HUVEC co-cultures may stimulate osteoblast maturation of DFSCs. Therefore, the secretion of angiogenic factors from HUVECs may play a role in the osteogenic differentiation of DFSCs.

Assessment of functional improvement with temporalis myofascial flap after condylectomy in elderly patients with anterior disc displacement without reduction and an erosive condylar surface.

BACKGROUND: The purpose of this study was to investigate the functional effects of temporalis myofascial flap after condylectomy, with or without disc removal, in elderly patients with anterior disc displacement (ADD) without reduction and an erosive condylar surface of the temporomandibular joint (TMJ). METHODS: A total of 15 joints from 11 elderly patients (71-78 years old) were included. The patients had pain, mandibular dysfunction symptoms, and unilateral or bilateral ADD as well as an erosive condylar surface of the TMJ. All patients underwent temporalis myofascial flap reconstruction after condylectomy, with or without disc removal. If the maximal mouth opening (MMO) remained <35 mm after condylectomy, coronoidotomy was also performed. Self-assessed pain and mandibular function, including MMO and protrusive and lateral movements, were evaluated. RESULTS: No patient experienced serious complications. Most measurements improved significantly after surgery compared to preoperatively. Most patients achieved nearly-normal mouth opening at 4 weeks after surgery. Although most patients felt discomfort during active postoperative physiotherapy, no patient reported serious pain during the follow-up period. CONCLUSION: Although nonsurgical therapy is often the first treatment choice for ADD without reduction of the TMJ, surgical intervention involving condylectomy and temporalis myofascial flap reconstruction may be a reasonable first option for elderly patients with an erosive condylar surface of the TMJ.

Time-Dependent Clinical Results of Rotating-Platform Total Knee Arthroplasty According to Mechanical Axis Deviation

PURPOSE: We hypothesized that the low contact stress (LCS) posterior stabilization system in knees with 3degrees deviation). The clinical assessments were performed using the Knee Society score and Hospital for Special Surgery systems and Western Ontario and McMaster Universities index. RESULTS: The survival rate was 97.4% in Group 1 and 96.8% in Group 2. No statistically significant intergroup difference was observed in the clinical scores before surgery and since 1 year after surgery (p>0.05). However, a significant intergroup difference was noted between 6 months to 1 year after surgery (p<0.001). Less than 2 mm radiolucent lines were found more frequently in Group 2. Time-dependent improvement was noted within one year after TKA in both groups. CONCLUSIONS: Most of the expected improvements were achieved at 6 months after surgery in Group 1 and at 1 year after surgery in Group 2. The present study suggests that the LCS system yields time-dependent improvement regardless of coronal alignment deviation.

Posterior Cruciate Ligament: Focus on Conflicting Issues

There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed.

Remnant Preservation is Helpful to Obtain Good Clinical Results in Posterior Cruciate Ligament Reconstruction: Comparison of Clinical Results of Three Techniques

BACKGROUND: The purpose of the present study was to compare the clinical results of 3 posterior cruciate ligament reconstruction techniques according to the time from injury to surgery and remnant PCL status and to evaluate the efficiency of each technique. METHODS: The records of 89 patients who underwent primary PCL reconstructions with a posterolateral corner sling were analyzed retrospectively. Thirty-four patients were treated by anterolateral bundle (ALB) reconstruction with preservation of the remnant PCL using a transtibial tunnel technique in the acute and subacute stages of injury (group 1). Forty patients were treated with remnant PCL tensioning and an ALB reconstruction using the modified inlay technique in the chronic stage (group 2), and fifteen patients were treated with double-bundle reconstruction using the modified inlay technique (group 3). The double-bundle reconstruction was performed if there was a very weak or no PCL remnant. RESULTS: The mean side-to-side differences in posterior tibial translation on the stress radiographs were reduced from 10.1 +/- 2.5 mm in group 1, 10.6 +/- 2.4 mm in group 2, and 12.8 +/- 3.2 mm in group 3 preoperatively to 2.3 +/- 1.4 mm in group 1, 2.3 +/- 1.5 mm in group 2, and 4.0 +/- 2.5 mm in group 3 at the last follow-up (p < 0.001, p < 0.001, and p < 0.001, respectively). Statistical analyses revealed that group 1 and group 2 were similar in terms of side-to-side difference changes in posterior tibial translation on the stress radiographs; however, group 3 was inferior to group 1 and group 2 at the last follow-up (p = 0.022). The clinical results were not significantly different among the three groups. CONCLUSIONS: Excellent posterior stability and good clinical results were achieved with ALB reconstruction preserving the injured remnant PCL in the acute and subacute stages and remnant PCL tensioning with ALB reconstruction in the chronic stage. The PCL injuries could be surgically corrected with different techniques depending on both the remnant PCL status and the interval between the knee trauma and operation.

Recent Evolution of Cruciate Ligament Surgery of the Knee

No abstract available.

Comparison of the Clinical Outcomes after Total Knee Arthroplasty with the LCS Rotating Platform Mobile Bearing Knee System and the PFC Sigma RP-F Mobile Bearing Knee System

BACKGROUND: We compared clinical outcomes after total knee arthroplasty with the Low Contact Stress (LCS) rotating platform mobile bearing knee system and the Press Fit Condylar Sigma rotating platform high flexion (PFC Sigma RP-F) mobile bearing knee system. METHODS: Fifty cases of total knee arthroplasty were performed with the PFC Sigma RP-F mobile bearing knee system and sixty-one cases were performed with the LCS mobile bearing total knee arthroplasty. The average duration of follow-up was 2.9 years. RESULTS: The mean Hospital for Special Surgery (HSS) knee score was 62.1 (range, 52 to 75) in the LCS group and 61.9 (range, 50 to 74) in the Sigma RP-F group preoperatively, and 90.1 (range, 84 to 100) in the LCS group and 89.8 (range, 83 to 100) in the Sigma RP-F group at the final follow-up. The mean preoperative flexion contracture was 6.7degrees (range, 0degrees to 10degrees) in the LCS group and 9.3degrees (range, 0degrees to 15degrees) in the Sigma RP-F group preoperatively. The mean range of motion was 124.6degrees (range, 105degrees to 150degrees) in the LCS group and 126.1degrees (range, 104degrees to 145degrees) in the Sigma RP-F group at the final follow-up. CONCLUSIONS: After a minimum duration of follow-up of two years, we found no significant differences between the two groups with regard to the range of knee motion or the clinical or radiographic results.

Effects of Mitomycin C on Scleral Collagen Fibrils According to Atomic Force Microscopy

PURPOSE: To investigate the effects of mitomycin C on the scleral collagen surfaces using atomic force microscopy (AFM). METHODS: Two non-contact mode AFM machines were used to observe changes in the morphological characteristics of human scleral surfaces before and after one, three, and five minutes of 0.02% mitomycin C application. Based on AFM topography and deflection images of the collagen fibril, the morphological characteristics of scleral fibrils including the fibril diameter and D-period were measured using the line profile. RESULTS: The sclera collagen fibril treated with 0.02% mitomycin C for one minute did not show any significant increases in mean fibril diameter (155.04 +/- 17.46 nm) or mean D-periodicity (70.02 +/- 3.33 nm), compared to those of the control group. However, the scleral collagen fibrils treated with 0.02% mitomycin C for three and five minutes showed significant increases in mean fibril diameter (182.33 +/- 16.33 nm, 199.20 +/- 12.40 nm, respectively) and mean D-periodicity (70.27 +/- 13.66 nm, 72.75 +/- 19.32 nm, respectively), compared to those of the control group. CONCLUSIONS: The present study examined the structural changes in the scleral collagen fibrils before and after mitomycin C application according to atomic force microscopy. The results indirectly suggest that three or more minutes of 0.02% mitomycin C application affects the morphology of scleral collagen.

Cementless Total Hip Arthroplasty Using a Modular Femoral Component in Patients with Femoral Head Osteonecrosis: Comparison of Metal-on-Metal and Ceramic-on-Ceramic Articulation

PURPOSE: The purpose of this study was to evaluate the clinical and radiological outcomes after total hip arthroplasty using the S-ROM modular system for osteonecrosis of the femoral head, and to compare the results between the groups using metal-on-metal articulation and ceramic-on-ceramic articulation. MATERIALS AND METHODS: Sixty-six patients (78 hips) with osteonecrosis of the femoral head were evaluated after primary total hip arthroplasty between January 2001 and December 2004, using an S-ROM proximal modular femoral stem. The average follow-up was 77 months (range, 60 to 122 months) and all patients were followed for more than five years. RESULTS: The average Harris hip score improved from 53 points to 88.5 points at the final follow-up. At the latest radiologic evaluation, sixty-seven stems had bony ingrowth stability, and 10 stems had stable fibrous ingrowth. However, one stem had diffuse extensive osteolysis and loosening, which was revised at 9 years. Postoperative complications included 4 cases of heterotrophic ossificiation, 1 case of linear fracture after insertion of the femoral stem, 1 case of dislocation, 2 cases of infection, and 1 case of extensive osteolysis and loosening. There were 3 cases of revision and Kaplan-Meier survivorship analysis with revision estimated at a 95.7% chance of survival for the femoral component during 122 months. CONCLUSION: Our study showed that total hip arthroplasty using the S-ROM modular system with metal-on-metal articulation or ceramic-on-ceramic articulation had favorable clinical and radiological mid- to long-term results.

The Influence of Tibial Positioning on the Diagnostic Accuracy of Combined Posterior Cruciate Ligament and Posterolateral Rotatory Instability of the Knee

BACKGROUND: To determine if tibial positioning affects the external rotation of the tibia in a dial test for posterolateral rotatory instability combined with posterior cruciate ligament (PCL) injuries. METHODS: Between April 2007 and October 2007, 16 patients with a PCL tear and posterolateral rotatory instability were diagnosed using a dial test. The thigh-foot angle was measured at both 30degrees and 90degrees of knee flexion with an external rotation stress applied to the tibia in 2 different positions (reduction and posterior subluxation). The measurements were performed twice by 2 orthopedic surgeons. RESULTS: In posterior subluxation, the mean side-to-side difference in the thigh-foot angle was 11.56 +/- 3.01degrees at 30degrees of knee flexion and 11.88 +/- 4.03degrees at 90degrees of knee flexion. In the sequential dial test performed with the tibia reduced, the mean side-to-side difference was 15.94 +/- 4.17degrees (p < 0.05) at 30degrees of knee flexion and 16.88 +/- 4.42degrees (p = 0.001) at 90degrees of knee flexion. The mean tibial external rotation was 5.31 +/- 2.86degrees and 6.87 +/- 3.59degrees higher in the reduced position than in the posterior subluxation at both 30degrees and 90degrees of knee flexion. CONCLUSIONS: In the dial test, reducing the tibia with an anterior force increases the ability of an examiner to detect posterolateral rotary instability of the knee combined with PCL injuries.

Comparative Study of ACL Double-bundle Reconstruction with and without Functional Knee Brace: Minimum 1-year Follow-up Results / 대한정형외과학회잡지

PURPOSE: To compare the clinical efficacy after an arthroscopic ACL double-bundle reconstruction with and without functional knee brace. MATERIALS AND METHODS: Between July 2004 and May 2006, fifty patients who underwent an ACL double-bundle reconstruction with and without a functional knee brace for more than a 1-year follow-up were evaluated. The patients were treated with brace (Group 1, 22 cases) or without (Group 2, 28 cases) a brace after surgrey. Stability was assessed by maximal manual testing with a KT-1000 arthrometer, anterior stress radiographs using the Telos device and a lateral pivot shift test. The clinical results were assessed by the OAK (Orthopadische Arbeitsgruppe Knie) score, IKDC (International Knee Documentation Committee) score, mid thigh circumference and the range of motion. RESULTS: More than one year after surgery, average of OAK score, IKDC score, lateral pivot shift test of the stability results and maximal manual testing with the KT-1000 arthrometer, stress radiographs with the Telos device, mid thigh circumference difference, range of motion of the clinical results were similar in both groups. CONCLUSION: An ACL double-bundle reconstruction produces similar stability and clinical results regardlness of whether or not a functional knee brace is used.

A Comparison of Patella Retention versus Resurfacing in Total Knee Arthroplasty: A Minimum 7 Year Follow-up / 대한정형외과학회잡지

PURPOSE: To evaluate and report the clinical and radiological results of patients that had undergone patellar retention and resurfacing during total knee arthroplasty. MATERIALS AND METHODS: From July 1993 to December 1999, 54 patients (73 cases) underwent total knee arthroplasty by one surgeon. We divided these patients into the patellar retention group and patellar resurfacing group, and compared the clinical and radiological results of the two groups. The indications of patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. In these cases, osteophytes of the patella were removed and marginal electrocauterization was performed. There were 32 patients (41 cases) in the patellar retention group and 22 patients (32 cases) in the patellar resurfacing group. The mean follow-up period was 106.7 months in the patellar retention group and 93.6 months in the patellar resurfacing group. We evaluated the patients using the knee rating system of the American Knee Society (knee score and functional score), knee arthroplasty rating system of the Hospital for Special Surgery (HSS score), patellofemoral score, range of motion of the knee joint, and performed a radiological evaluation by use of the radiographical evaluation system of the Knee Society at the last follow-up period. Also, to evaluate patellofemoral congruence, we used Keblish's method. RESULTS: At the last follow-up, the mean knee score and functional score were 90.4 and 75.5 for the patellar retention group, and 86.1 and 70.0 for the patellar resurfacing group, respectively (p=0.29, p=0.27). The HSS score was 85.2 for the patellar retention group and 84.8 for the patellar resurfacing group (p=0.30). The Bristol patellar score and Lonner Patellofemoral score were 8.7 and 82.0 for the patellar retention group and 8.8 and 85.6 for the patellar resurfacing group, repectively (p=0.86, p=0.86). The mean value of the patellofemoral score was slightly higher in the patellar resurfacing group, but statistically there was no difference between the two groups. There were also no statistically differences in the others parameters. CONCLUSION: We obtained favorable results by selective patellar resurfacing total knee arthroplasty, although there were no significant differences for both the patellar retention and resurfacing group. We believe that it may be better to select a proper indication than to just follow the preference of the surgeon for patellar resurfacing.

Matrix Metalloproteinase-1 and Transforming Growth Factor-beta1 Expression during Distraction Osteogenesis and Fracture Healing of the Rat / 대한정형외과학회잡지

PURPOSE: To evaluate the temporal and spatial expression of Transforming Growth Factor-beta1 and Matrix Metalloproteinase-1 in distraction osteogenesis and fracture healing models. MATERIALS AND METHODS: Distraction osteogenesis was performed on the tibial diaphyses of Sprague- Dawley rats (latent period for 1 week, distraction for 2 weeks). The rats were euthanized at each week and the level of mRNA expression was assessed by real-time RT PCR and immunohistochemical staining. RESULTS: Although the level of TGF-beta1 mRNA and MMP-1 mRNA expression was increased during distraction osteogenesis and fracture healing, the level of mRNA expression was significantly higher in the distraction phase in the distraction group than in the fracture healing group at the same phase. After the distraction phase, the level of mRNA expression in both groups decreased to the base line. The peak expression of mRNA was followed by that of TGF-beta1 mRNA. Immunohistochemical staining revealed that TGF-beta1 was expressed mainly in the osteoblast and endothelial cells, and MMP-1 was expressed mainly in the endothelial cells of the vessel. CONCLUSION: There is specific time sequence in the expression of TGF-beta1 and MMP-1 during fracture healing and distraction osteogenesis. These results suggest that TGF-beta1 expression might be associated with the angiogenesis induced by MMP-1 expression during new bone formation.

Polymorphisms and haplotypes of integrinalpha1 (ITGA1) are associated with bone mineral density and fracture risk in postmenopausal Koreans.

INTRODUCTION: ITGA1 is involved in the early remodeling of osteoarthritic cartilage and plays an essential role in the regulation of mesenchymal stem cell proliferation and cartilage production. We investigated the association between bone parameters and ITGA1 polymorphisms and their haplotype linkage disequilibrium (LD) blocks (BL_hts). Genetic susceptibility to osteoporosis was studied in 946 postmenopausal Korean women. METHODS: We identified 67 genetic polymorphisms in ITGA1 region by direct sequencing (n = 114). Eight SNPs were genotyped to further investigate their potential involvement in osteoporosis in postmenopausal women (n = 946). Areal BMD of the lumbar spine and proximal femur was measured using dual-energy X-ray absorptiometry. RESULTS: The SNPs, +73187C>T (exon 3) and +76969T>G (intron 5), and their BL_hts were associated with bone mineral density (BMD) at various femur sites (p = 0.009-0.05). Moreover, +159174A>C (intron 28) and its haplotype BL3_ht1 showed a highly significant association with risk of non-vertebral fracture (p = 0.002-0.005) and the minor allele of +159174A>C showed a protective effect. CONCLUSIONS: These results are suggestive of the association of ITGA1 with osteoporosis and related risk in postmenopausal women.

Neurolymphomatosis Involving Sciatic Nerve: A Case Report / 대한정형외과학회잡지

The term "Neurolymphomatosis" includes the infiltration of the peripheral nervous system by lymphoma and nontumor lymphocytes. A neurolymphomatosis has not been classified as a distinct entity. Hence, its characteristic symptoms are often missed, and oncologists or neurological consultants fail to obtain an accurate diagnoses. We encountered a case of non-Hodgkins lymphoma involving the sciatic nerve, which has never been reported in the orthopedic literature in Korea. We report a case of neurolymphomatosis with a brief review of the literature.

Heterotopic Bone Formation in Patient who Underwent a Posterior Cruciate Ligament Reconstruction using the Inlay Method and Posterolateral Corner Sling with a Tibia Tunnel: A Case Report / 대한정형외과학회잡지

We describe a case of posterolateral capsular heterotopic ossification requiring a surgical excision after a PCL (Posterior Cruciate Ligament) reconstruction using the modified inlay method and PLCS (posterolateral corner sling) with a tibia tunnel. A 21-year-old female patient had suffered a blunt proximal tibial direct trauma 6 months earlier. She did not experience limb ischemia or a pulse deficit before she visited our out patient clinic. She had not suffered any trauma in other sites, and showed a range of motion of 0 to 30degrees at 4 months after surgery. There was no specific finding on the X-ray images. Arthroscopic adhesiolysis was performed and her range of motion increased to 0 to 120degrees. However, 6 months after the initial operation, she showed ankylosis and heterotopic ossification at the posterior aspect, which was surgically removed at 12 months postoperatively. After the second surgery, there was no recurrence and she showed a 0 to 140degrees range of motion at postoperative 42 months.

Enhanced recovery of arsenite sorbed onto synthetic oxides by L-ascorbic acid addition to phosphate solution: calibrating a sequential leaching method for the speciation analysis of arsenic in natural samples.

Stripping voltammetry capable of detecting 0.3microg/L arsenate and arsenite was applied for speciation analysis of arsenic sorbed onto synthetic ferrihydrite, goethite at As/Fe ratio of approximately 1.5mg/g with or without birnessite after sequential extraction using 1M phosphate (24 and 16 h) and 1.2M HCl (1h). Precautions to avoid oxygen were undertaken by extracting under anaerobic conditions and by adding 0.1M l-ascorbic acid to 1M NaH(2)PO(4) (pH 5). Addition of l-ascorbic acid did not reduce As(V) to As(III). The recovery rate for As(III) using l-ascorbic acid for extraction (pH 5) but not for adsorption was 81% and 74% of total sorbed As, and was 99% and 97% of extracted As for ferrihydrite and goethite, respectively. Birnessite oxidized most As(III) during the adsorption procedure. l-ascorbic acid used both in adsorption and extraction procedures improved the recovery of As(III) to 79-94% for ferrihydrite-birnessite and 57-94% for goethite-birnessite systems with Fe/Mn ratios of 7, 70, 140 and 280g/g.

Tensioning of Remnant Posterior Cruciate Ligament with a Reconstruction of the Anterolateral Bundle in Chronic PCL Injuries / 대한정형외과학회잡지

PURPOSE: This report introduces a new method for tensioning the remnant PCL with a reconstruction of the anterolateral (AL) bundle of the PCL using a modified tibial inlay technique with an assessment of the outcome of this method in chronic PCL injury. MATERIALS AND METHODS: From January 1998 to August 2003, eighty six patients was underwent tensioning of a laxed remnant PCL with a reconstruction of the anterolateral bundle of the PCL. Of these, fifty two patients who were followed up for more than 2 years were evaluated. Tensioning was performed using a distal transfer of the tibial attachment with the posteromedial approach in the supine position. The AL bundle of the PCL was reconstructed with 4 bundles of a hamstring autograft or tibialis anterior tendon allograft. The stability was assessed objectively using stress radiographs with the Telos(R) device and the maximal manual test with the KT-1000 arthrometer. The clinical results were assessed by the IKDC (International Knee Documentation Committee) and OAK (Orthopadische Arbeitsgruppe Knie) scores. The posterior drawer test, varus stress test, posterolateral drawer test and dial test in 30 degrees and 90 degrees flexion were performed for a physical examination. RESULTS: The average side to side difference of the posterior tibial translation in stress radiographs with the Telos(R) device decreased from 10.4+/-2.0 mm to 2.2+/-1.0 mm. The average side to side difference in the maximal manual test with the KT-1000 arthrometer also decreased from 8.2+/-1.5 mm to 1.9+/-1.0 mm. The final IKDC score was A in eleven (21.2%), B in thirty-five (67.3%) and C in six (11.5%) patients. The average OAK score improved from 64.3+/-8.9 to 90.8+/-7.2. CONCLUSION: Tensioning of the laxed remnant PCL with a reconstruction of the AL bundle in chronic PCL injuries showed good clinical results and excellent posterior stability.

Tensioning of Lax Anterior Cruciate Ligament and Augmentation with Double Hamstring Tendon : A Report of Surgical Technique / 대한정형외과학회잡지

PURPOSE: To introduce a new surgical technique for tensioning a lax ruptured anterior cruciate ligament (ACL) with good continuity and augmenting it using the double hamstring tendon. MATERIALS AND METHODS: The clinical results were obtained from 5 cases that had been followed up for more than 1 year. Most were sports injuries but one case was the result of a traffic accident. The parameters used for examining the clinical results were the Lachman test, a pivot shift test, KT-1000 arthrometer, pull stress view, IKDC and OAK score before surgery and at the last follow-up. Three cases were checked preoperatively by MRI. Three cases who had an associated posterolateral rotatory instability underwent a reconstruction using a posterolateral corner sling through the fibular head. RESULTS: The Lachman test and pivot shift test, which were positive preoperatively, were converted to negative in all patients at the last follow-up. Two cases were C grade and two cases were D grade. These patients were converted to A grade, but one C grade case was converted to B grade in the IKDC score. In the OAK score, the average score was 68.5 (57 to 90) before surgery, and 91.2 (79 to 98) after surgery. In the KT-1000 arthrometer and pull stress view, the mean side-to-side difference was 5.6 (5 to 6) mm and 7 (5 to 8) mm before surgery and 1.5 (1 to 3) mm, 0.3 (0 to 1) mm, after surgery, respectively, except for one case who showed laxity of the contralateral side. CONCLUSION: Tensioning of a lax ACL and hamstring tendon augmentation is an effective method for correcting a lax ACL to restore joint stability and preserve the remnant proprioception.